Activity does everything. No collaborators.

MainActivity.kt

class MainActivity : AppCompatActivity() {
   private val firebaseAuth by inject<FirebaseAuth>()
   var providers = Arrays.asList(
           AuthUI.IdpConfig.Builder(AuthUI.EMAIL_PROVIDER).build(),
           AuthUI.IdpConfig.Builder(AuthUI.GOOGLE_PROVIDER).build())

   override fun onCreate(savedInstanceState: Bundle?) {
       super.onCreate(savedInstanceState)
       setContentView(R.layout.activity_main)
       createContentButton.setOnClickListener({
           val intent = if (firebaseAuth.currentUser != null) {
               Intent(this, NewContentActivity::class.java)
           } else {
               AuthUI.getInstance()
                       .createSignInIntentBuilder()
                       .setAvailableProviders(providers)
                       .build()
           }
           startActivity(intent)
       })
   }
}